1. Field of the Invention
The present invention is related to an image forming method that forms an image by jetting ink from a recording head and an information forming apparatus using the image forming method.
2. Description of the Related Art
Conventionally, it is known that an inkjet type image forming apparatus having a carriage mounted with a recording head scans in a main scanning direction and jets ink drops for forming an image on a recording medium moving in a sub-scanning direction.
Such an image forming apparatus includes plural kinds of driving patterns such as “a print driving” for jetting ink drops, “an ink purge driving” for cleaning nozzles to recover from clogging caused by a long-time unused condition, and “minor driving” for maintaining nozzles to prevent clogging.
Further, the image forming apparatus needs to output a drive pattern (drive waveform) for driving the recording head. There are several proposed techniques for outputting such a drive pattern.
As a drive pattern, there is known a technique of “pull-up/pull-down” that controls electric potential (potential) to be a predetermined electric potential according to requirements for a recording head, in which a “pull-up” pulls up potential from zero to a reference potential and “pull-down” pulls down the potential to zero potential after the drive pattern is output.
However, for conventional pull-up/pull-down operations, when it is required to continuously execute different kinds of recording head driving operations, a pull-down operation is required to once pull down the potential to zero after the driving of the head being executed at a predetermined time is completed. Thereafter, a pull-up operation is required to pull up the potential to a reference potential depending on the kind of the recording head driving operation. For this reason, it was difficult to promptly cope with the need to pull down and pull up the potential of the drive waveform.
Further, as a different issue, extra electric power is necessary because the pull-up operation raises potential from zero potential and the pull-down operation drops potential to zero potential every time when another recording head driving operation is requested.
In order to improve the efficiency of recording head driving for a conventional case, a technique is shown where the environment temperature is preliminarily measured and the drive pattern is adjusted in a potential direction and a time base direction (see Japanese Patent Application Publication 2006-264287). This technique provides an optimum driving potential to be selected according to each driving condition.
However, the above technique does not take into consideration a recording head which outputs a different kind of drive pattern by switching to another waveform pattern (drive pattern) immediately after an output of a certain kind of drive pattern (waveform pattern), and there is an issue remaining for immediate switching of an output waveform pattern and reducing power consumption.